Patch "firmware: dmi_scan: Only honor end-of-table for 64-bit tables" has been added to the 4.1-stable tree

Patch "firmware: dmi_scan: Only honor end-of-table for 64-bit tables" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    firmware: dmi_scan: Only honor end-of-table for 64-bit tables

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     firmware-dmi_scan-only-honor-end-of-table-for-64-bit-tables.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 17cd5bd5391e6e7b363d66335e1bc6760ae969b9 Mon Sep 17 00:00:00 2001
From: Jean Delvare <jdelvare@suse.de>
Date: Thu, 25 Jun 2015 09:06:55 +0200
Subject: firmware: dmi_scan: Only honor end-of-table for 64-bit tables

From: Jean Delvare <jdelvare@suse.de>

commit 17cd5bd5391e6e7b363d66335e1bc6760ae969b9 upstream.

A 32-bit entry point to a DMI table says how many structures the table
contains. The SMBIOS specification explicitly says that end-of-table
markers should be ignored if they are not actually at the end of the
DMI table. So only honor the end-of-table marker for tables accessed
through 64-bit entry points, as they do not specify a structure count.

Fixes: fc43026278 ("dmi: add support for SMBIOS 3.0 64-bit entry point")
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/firmware/dmi_scan.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -89,9 +89,9 @@ static void dmi_table(u8 *buf,
 
 	/*
 	 * Stop when we have seen all the items the table claimed to have
-	 * (SMBIOS < 3.0 only) OR we reach an end-of-table marker OR we run
-	 * off the end of the table (should never happen but sometimes does
-	 * on bogus implementations.)
+	 * (SMBIOS < 3.0 only) OR we reach an end-of-table marker (SMBIOS
+	 * >= 3.0 only) OR we run off the end of the table (should never
+	 * happen but sometimes does on bogus implementations.)
 	 */
 	while ((!dmi_num || i < dmi_num) &&
 	       (data - buf + sizeof(struct dmi_header)) <= dmi_len) {
@@ -110,8 +110,13 @@ static void dmi_table(u8 *buf,
 
 		/*
 		 * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
+		 * For tables behind a 64-bit entry point, we have no item
+		 * count and no exact table length, so stop on end-of-table
+		 * marker. For tables behind a 32-bit entry point, we have
+		 * seen OEM structures behind the end-of-table marker on
+		 * some systems, so don't trust it.
 		 */
-		if (dm->type == DMI_ENTRY_END_OF_TABLE)
+		if (!dmi_num && dm->type == DMI_ENTRY_END_OF_TABLE)
 			break;
 
 		data += 2;


Patches currently in stable-queue which might be from jdelvare@suse.de are

queue-4.1/firmware-dmi_scan-only-honor-end-of-table-for-64-bit-tables.patch